The present invention relates to a device for displacing a switch blade between a position on a stock rail and a position at a distance from the stock rail.
Railroad switches are fitted with locking devices for the purpose of securing switch blades, as disclosed for instance in European patent application EP 0 885 795 A1. This European patent application discloses the function of a modern locking device (latching closure CKA). Said document discloses not only the locking and unlocking but also the displacement of the switch blades, which in the case of a latching closure take place with the aid of a locking rod and a locking catch. The switch blade connected to the locking catch via a locking bearing is brought into contact with the associated stock rail during the locking procedure of the locking rod, during which the locking catch is guided under the stock rail and pressed upward against the foot of the stock rail, that is, against the locking support arranged at the foot of the stock rail, by the locking rod for locking the switch blade.
Particularly in the case of switch blades which are quite long, as they need to be for the larger radiuses, undesirable oscillations occur during use. These switch blades are furthermore at increased risk of torsion, as a result of which the switch blade can lift clear of the stock rail. It is known that document EP 0 624 508 A1 discloses a locking device which seeks to achieve a tight connection between the switch blade and the stock rail. This is achieved by providing the locking bearing connected to the switch blade with an elongation which presses against a locking support firmly connected to the stock rail when the locking device locks, as a result of which the switch blade pivots about the locking bearing and is pressed tightly against the stock rail.
Moreover German patent application DE 43 15 200 A1 discloses a locking device according to the document EP 0 624 508 A1 mentioned above. Said device is integrated into a hollow-section cross-tie, enabling automatic tamping of the track ballast in the region of the switch displacement device, that is, especially in the region of the tips of the switch blades.
It is common to all the above-mentioned reference documents that the locking support at the foot of the stock rail is held by gripping the foot of the stock rail on both sides and/or the locking catch is held in the locking bearing which is directly fastened to the switch blade. It is therefore easy to understand that, particularly in countries such as the USA, the UK and Japan, which have a great plurality of track and switch blade profiles, a correspondingly large number of different locking supports and/or locking bearings needs to be held in inventory and used in line with demand. It is thus expensive and time-consuming to store and use such items in this way in view of the plurality of profiles which exist. Even with only slight differences between one profile and another there is a risk that the construction team, which as a rule installs switches when the line is open to traffic, and is therefore always working under a certain amount of time pressure, might get the profiles mixed up. Such mistakes however can lead to premature wear or even to a serious malfunction.